GEOS comes with its own ROM and bypasses the Commodore 64 "Kernal". This one is a GUI that runs on existing ROM.
I used GEOS unironically in high school. I had two 1541 floppy drives which really cut down on the disk swapping and I was able to do productive work. Ultimately I used my employee discount to upgrade to a Tandy 1000 TL that would boot into DeskMate from ROM and took it to college, leaving the C64 in the dust. I still have all the stuff but not the time.